Crystal Oscillators

A crystal oscillator is an electronic circuit that uses the mechanical resonance of a vibrating crystal (usually quartz) to generate a precise frequency. It's widely used for timing references in clocks, microcontrollers, radios, and communication systems.

Key Features:

• High frequency stability
• Low phase noise
• Temperature-sensitive (can be compensated - TCXO, OCXO)
• Typical frequencies: 32.768 kHz (real-time clocks), 4 MHz to 50 MHz (MCUs)

Common Types:

Typical Circuit (for MCU):

XTAL1 (MCU) —||— Crystal —||— XTAL2 (MCU)
               C1             C2
                 \           /
                  \         /
                   GND     GND

C1, C2: Load capacitors (typically 10–22 pF), value depends on crystal specs.